ATLANTA – Some patients experienced improvement in at least one neurocognitive domain up to 3 years after having bariatric surgery, a small, systematic review has shown.
The most significant improvements were reported in memory, with nine studies showing some statistically significant improvement in a post-bariatric surgery cohort. Four studies showed statistically significant improvement in attention and executive function, and two did so in language.
Dr. Gurneet S. Thiara, a psychiatry resident at the University of Toronto, presented the findings during a scientific session at this year’s annual meeting of the American Psychiatric Association.
Dr. Gurneet Thiara
Because the studies that form the basis of the analysis did not follow a standard pre-surgery neurocognitive assessment, the actual scope of bariatric surgery’s impact on neurocognition is hard to determine. This shortcoming provides evidence that instituting a standardized method of psychiatric assessment pre-bariatric surgery could help clinicians better anticipate overall neurocognitive outcomes, he said.
“It’s hard to pinpoint the one domain that affects [this cohort] most,” said Dr. Thiara.
One study included in the analysis showed no neurocognitive improvement, although Dr. Thiara noted this was possibly due to the under- or non-reporting of negative outcomes by researchers who conducted studies that might have met his inclusion criteria.
Dr. Thiara and his colleagues were not able to draw conclusions as to which patients would be affected in which domains and by what mechanism of action. Their analysis did suggest possible relationships between gastric bypass and changes in metabolism, levels of leptin and ghrelin, vascular function, hypoperfusion in the brain, and even shifts in the gut microbiome.
Dr. Thiara sought studies with bariatric surgery patients whose neurocognitive and psychological outcomes were followed anywhere from one to three years post-surgery. After analyzing 422 studies published between January 1990 and August 2015, only ten studies, with patient sample sizes ranging from 10 to 156, met the criteria.
The study was not intended to determine a relationship between neurocognitive outcomes and type of bypass surgery performed, but Dr. Thiara said the majority of the procedures analyzed tended to be Roux-en-Y rather than the gastric bypass sleeve.
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